susan candiotti was there yesterday. she is live this morning in bridgeport, connecticut. good morning, susan. what can you tell us? what is threat last on the investigation? >> good morning, poppy. well, investigators for the national transportation safety board have been added all night long. and, look, they're working even at this hour you can see some of that of the opaeration going on at this time. they have bulldozers down there and trying to remove some of the cars which have already been cleared from the track and you can see a little more closely now some of the damage. parts of cars peeled back. they've got, clearly, a lot of work ahead of them. here to tell us more about it is board member earl. earl, you've been at it since yesterday morning and your team is looking over everything. you're making a bit of progress. one thing you told us you're concentrating on is you discovered a fracture on one part of the rail, involving one of the trains. the one that derailed yesterday. jumped the track. what are you looking for? >> well, we're really trying to understand w